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Sodium salicylate prevents TNF alpha‐induced reductions in insulin‐stimulated eNOS ser1177 phosphorylation but not Akt in human aortic endothelial cells
Author(s) -
Younatham Ramsan,
Siefers Kyle,
WegmanPoints Lauren,
Pierce Gary
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.802.5
Subject(s) - insulin , protein kinase b , medicine , endocrinology , sodium salicylate , proinflammatory cytokine , phosphorylation , nitric oxide , tumor necrosis factor alpha , insulin resistance , enos , chemistry , insulin receptor , nitric oxide synthase , endothelial dysfunction , inflammation , biochemistry
Proinflammatory cytokines, such as tumor necrosis factor alpha (TNFa), may contribute to vascular endothelial dysfunction in obesity/diabetes through the promotion of endothelial cell insulin resistance. Insulin‐stimulated increases in endothelial cell nitric oxide production involves phosphorylation of endothelial nitric oxide synthase serine 1177 (p‐eNOS ser1177 ) largely by protein kinase B (Akt). Sodium salicylate (Na Sal), a non‐acetylated salicylate with anti‐inflammatory actions, activates AMP‐activated protein kinase that also can directly phosphorylate eNOS ser1177 . We tested the hypothesis that in vitro pretreatment with Na Sal would prevent TNFa‐induced reductions in insulin‐stimulated p‐eNOS ser177 but not p‐AkT ser473 in human aortic endothelial cells (HAECs). In serum starved HAECs, time course experiments indicated that insulin‐ (10 nM) stimulated maximal phosphorylation of AkT ser473 occurred at 30 min (Western blotting, n=3, P<0.05) and eNOS ser1177 at 60 minutes (n=3, P<0.05). The insulin‐stimulated increase in p‐eNOS ser1177 at 60 minutes (n=3, P=0.001, vs. non‐insulin control) was abolished by TNFa (10 ng/ml, 2 hrs; n=3, P<0.05 vs. insulin), but pretreatment of HAECs with Na Sal (5 mM, 30 min) prevented the TNFa‐mediated decrease in p‐eNOS ser1177 (n=3; P=0.03 vs. insulin + TNFa). Insulin‐stimulated increase in p‐AkT ser473 at 30 minutes (n=3, P=0.008) tended to decrease after TNFa (n=3, P=0.09) but was not significantly altered by Na Sal (P=0.37). These data suggest that Na Sal protects against inflammation‐induced impairments in insulin‐stimulated phosphorylation ofeNOS ser1177 in aortic endothelial cells through non‐Akt signaling.